Solar panels of relatively small scale are typically constructed of a quadrilateral frame covered by glazing with an absorber mounted on a flat base beneath the glazing. U.S. Pat. No. 4,176,654 discloses a particularly satisfactory multi-tube strip of elastomeric material which serves as the basic component of the absorber to carry a heat exchange liquid. Such solar panel designs become less feasible as the size of the collector increases because of the problem of support of expansive glazing surfaces. One approach which has proved less than satisfactory, for example, has been to pressurize the air within a collector to inflate and thereby stretch its glazing, as suggested in U.S. Pat. No. 4,160,443.
It is the principal object of the present invention to provide a large scale solar collector which includes an expansive glazing of flexible translucent film but which relies on easily assembled inexpensive self-tensioning means for stretching the film over a frame. Solar collectors of this sort have particular application in industrial and commercial installations where the aethsetics of the unit are less important than low cost, ease of assembly and durability.